One useful class of materials is elastomer-bonding compositions (i.e., compositions that are capable of bonding to elastomer substrates). In some situations, it is useful to find elastomer-bonding compositions that are waterborne. Various polymers are known to be useful in one or more specific formulations that are capable of bonding to elastomer substrates. For example, US 2003/0158338 describes aqueous compositions useful for adhering elastomers to other substrates and lists a variety of polymers that may be included in such a composition, including halogen substituted olefin polymers and sulfonyl halide-substituted olefin polymers.
It is desired to make elastomer-bonding compositions that contain blends of two or more different polymers. In some cases, a blend of two or more different polymers is desired because each polymer, when used alone, provides some specific benefit to an elastomer-bonding composition. However, it has been discovered that when some of such blends are made, the resulting composition has poor shelf stability. For example, it is expected that blends of bromine substituted olefin polymer and halosulfonated olefin polymer will sometimes have poor shelf stability. It is known, for example, that solvent based adhesives that are blends of mixed-halogen substituted olefin polymer and halosulfonated olefin polymer sometimes have poor shelf stability. Likewise, it has been discovered that waterborne blends of mixed-halogen substituted olefin polymer and halosulfonated olefin polymer sometimes have poor shelf stability. It is desired to provide waterborne compositions that contain both bromine substituted olefin polymer and halosulfonated olefin polymer and that have improved shelf stability.